A 36 x 48 poster measures 36 inches wide by 48 inches tall — a 3 ft x 4 ft print, or about 91.4 x 121.9 cm (914 x 1219 mm), with a 3:4 portrait aspect ratio.
For the full breakdown, see our best 36 x 48 Poster guide.
Two numbers, one trap: the first figure is always width. Mix them up and a conference poster shows up rotated 90 degrees — a last-minute reprint at full price.
Exact 36 x 48 Dimensions In Inches, Feet, And Millimeters
A 36 x 48 poster equals 36 inches wide by 48 inches tall — 3 feet x 4 feet, 91.4 x 121.9 centimeters, or 914 x 1219 millimeters. The total print area is 1,728 square inches (36 × 48).
US print shops quote in inches, while many design templates and international collaborators work in millimeters or centimeters — the same object as 914 x 1219 mm or 91.4 x 121.9 cm. Knowing all three prevents a file from being resized by someone guessing at the conversion.
At 3 x 4 feet, this is a large-format poster: the standard US research and conference size, and also used for trade-show backdrops, retail displays, and lobby signage. For commercial printing, 36-inch roll widths are common in wide-format shops, so this format runs efficiently on standard equipment.
| Measurement | 36 x 48 (Portrait) | 48 x 36 (Landscape) |
|---|---|---|
| Inches | 36 W x 48 H | 48 W x 36 H |
| Feet | 3 ft x 4 ft | 4 ft x 3 ft |
| Millimeters | 914 x 1219 mm | 1219 x 914 mm |
| Centimeters | 91.4 x 121.9 cm | 121.9 x 91.4 cm |
| Aspect ratio | 3:4 | 4:3 |
| Print area | 1,728 sq in | 1,728 sq in |
| Pixels at 150 DPI | 5400 x 7200 px | 7200 x 5400 px |
| Pixels at 300 DPI | 10800 x 14400 px | 14400 x 10800 px |
If you would rather compare ready-made print options than build a file from scratch, this roundup of the best 36 x 48 posters covers tested picks worth a look before you commit to a print run.
Portrait Or Landscape — And The 3:4 Aspect Ratio
A 36 x 48 poster is portrait (36 wide, 48 tall) with a 3:4 aspect ratio; flip it to 48 x 36 and it becomes landscape with a 4:3 ratio. The numbers stay the same two measurements — only which one is width changes.
Aspect ratio is proportional, not a size. That’s why a 36 x 48 poster shares its exact 3:4 proportion with an 18 x 24 poster: artwork designed at any 3:4 ratio scales up to 36 x 48 without cropping, so a half-size proof and the final print show identical framing.
Not every size behaves this way. A 24 x 36 poster runs 2:3, not 3:4, so a file built for 24 x 36 will crop or letterbox when blown up to 36 x 48. Check the ratio before you scale.
Resolution And Viewing Distance
For a 36 x 48 conference poster viewed from 5–10 feet, 150 DPI is the standard target; 300 DPI suits prints people will inspect up close, and at this size that means a 10800 x 14400 px file.
Print guidance generally ranges from 150 to 300 DPI depending on how close the audience stands and what the piece is for. A research poster read from several feet away holds up at 150 DPI. A lobby or retail display that shoppers walk up to and study benefits from the higher figure.
Alphagraphics, in its writing on aspect ratio, treats proportion as the design constraint and resolution as the viewing-distance variable — two separate decisions. Get the ratio right so nothing crops, then set the pixel count to match how near your readers will be.
The Mistakes That Cost A Reprint
- Swapping width and height. 36 x 48 is portrait; 48 x 36 is landscape. Label your file accordingly.
- Assuming all posters share one ratio. 24 x 36 is 2:3; 36 x 48 is 3:4. They are not interchangeable when scaling.
- Treating physical size and aspect ratio as the same thing. The ratio is proportional; the measurements are the physical print.
- Designing at too low a resolution. A file that looks fine on a monitor can print soft if you ignore the 150–300 DPI range tied to viewing distance.
FAQs
Is a 36 x 48 poster the same as 3 x 4 feet?
Yes. Divide each measurement by 12 inches per foot and 36 x 48 inches becomes 3 feet x 4 feet. The two describe the identical print — one in inches, one in feet.
Can I resize an 18 x 24 design to this size without cropping?
Yes. Both share a 3:4 aspect ratio, so an 18 x 24 design scales up to 36 x 48 with identical framing and no cropping. Just make sure the source resolution holds up at the larger print size before scaling.
How many pixels is a 36 x 48 poster at 300 DPI?
At 300 DPI, a 36 x 48 poster requires 10800 x 14400 pixels. At 150 DPI the same poster needs 5400 x 7200 pixels, which is usually enough for viewing from five to ten feet away.
References & Sources
- AlphaGraphics. “Aspect Ratio” Explains how aspect ratio governs poster proportion and scaling.